yeager1

For engine block heaters, the type that go in the freeze plug holes work well and are cheap. These are not generally made for specific motors, but are generic to the freeze plug diameter- just measure yours and go to NAPA or Car Quest.
I've seen and used the style that mounts inline with your radiator hose (or heater hose)at work and the also work very well. The nice thing about these is they also heat the water in the radiator- the downside to that is radiators are made to shed heat so you will use up a lot more power for the same results as a block heater. JC Whittney sells these and I'm sure NAPA can get them too.
Oil heaters are nice if you’re in a really cold place. IMO the best ones are not the ones with the rod going into the oil pan (but they do work), but rather the ones that go on the bottom of the pan (I personally like the magnetic ones) because they heat the whole oil pan/oil supply. IMO in most areas they are not that necessary because if you already have a block heater, you will be pumping the cold oil (the pump itself creates heat) into an already warm block and it will warm up fairly quick anyway, but that’s just my 2 cents.